In a Reddit AMA thread, few members of UBISOFT Assassin's Creed III development team, answered questions about the upcoming PC release and plans for patches last night. And it seems like PC players will receive all the updates and patches that are released for console already.
Assassin's Creed III Creative Director Alex Hutchinson has confirmed:
Lots of bug fixes incoming! PC release will include the first two patches on release.
Senior community developer Gabe Graziani, also known as UBIGabe, elaborated few issues about PC, saying:
So, when PC launches, it will include ALL of the console patches out at the time (so, that includes any patches we might be releasing in between now and PC launch). In addition, PC has a special patch designed to ensure that everything runs as smoothly as possible.
We've added extra DX11 support for the PC version, so you'll notice some significant increases in texture resolution (double-res in most cases, but quadruple in some), TESSELLATION (which is like, the new DX11 hotness) and some other shader improvements that will have an impact, but aren't all that sexy to enumerate in a reddit post, hehe.
If you're going PC, I would opt for the Digital Deluxe version if it is available, because it comes strapped with tons of extra in-game content.
So, the PC version will come with additional patches, both those that have been or are just about to be released on consoles as well as some specific for the PC. I would say it will be less buggy than the console versions AT CONSOLE LAUNCH, but that the console and PC versions will be comparable at PC launch.
About Mouse and Keyboard players on PC, Alex Hutchinson confirmed:
PC will be fine AFAIK in terms of mouse and keyboard.
Assassin's Creed III is scheduled for November 20, 2012 release on PC while PS3 & XBOX360 versions were released on October 30th last month.